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The influence of Gaussian pinning on the melting scenario of a two-dimensional soft-disk system: First-order versus continuous transitionстатья
- Авторы: Fomin Yu D., Gaiduk Eu A., Tsiok E.N., Ryzhov V.N.
- Журнал: Physica A: Statistical Mechanics and its Applications
- Том: 644
- Номер: 129841
- Год издания: 2024
- Издательство: Elsevier BV
- Местоположение издательства: Netherlands
- Первая страница: 1
- Последняя страница: 13
- DOI: 10.1016/j.physa.2024.129841
- Аннотация: Two-dimensional systems are realized experimentally as thin layers on a substrate. The substratecan have some imperfections (defects of the crystalline structure, chemical impurities, etc.)with strong interactions with particles within and near the defects. Such randomly distributedcenters of strong interactions are called "pinning centers". The presence of random pinning cansubstantially change the behavior of the system. It not only shifts the melting point of thesystem, but can also change the melting scenario itself. In the present paper the influence ofGaussian pinning on the melting scenario of a two-dimensional system of soft disks is studied bymeans of molecular dynamics simulation. We randomly introduce into the system of soft disksa set of ‘‘pinning centers’’ which attract the particles via the Gauss potential. We observe thatincreasing the depth of a Gaussian well leads to a change in the melting scenario of the system: from melting occurring via a first-order liquid-hexatic transition followed by a continuous hexatic-crystal transition to two continuous transitions through an intermediate hexatic phase. We show that there are still two transition stages for strong disorder, but the melting scenario isqualitatively different from that for weak disorder. The results demonstrate that the simple kind of quenched disorder can significantly affect the melting scenario of two-dimensional systemsand offer the possibility of their application for the interpretation of complex experiments.
- Добавил в систему: Рыжов Валентин Николаевич